CVE-2002-0693Windows 2000 Vulnerability
Buffer overflow in the HTML Help ActiveX Control (hhctrl.ocx) in Microsoft Windows 98, 98 Second Edition, Millennium Edition, NT 4.0, NT 4.0 Terminal Server Edition, Windows 2000, and Windows XP allows remote attackers to execute code via (1) a long parameter to the Alink…
Published Oct 10, 2002 · Updated Apr 15, 2026
Key Facts
Patch immediately- CVE-2002-0693 is a high-severity vulnerability (CVSS 7.5 v2) affecting Windows 2000 (Microsoft), Windows 2000 Terminal Services (Microsoft), Windows 98 (Microsoft) and 4 more products.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 31% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Scores
CVSS v2
7.5
AV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS (30-day exploit likelihood)
31%
Higher than 98.2% of all scored CVEs
Exploit maturity
Proof of concept
ATLAS score
36/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Proof of concept
Public exploit code
1
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisorywin-html-help-bo(10253)
Description
Buffer overflow in the HTML Help ActiveX Control (hhctrl.ocx) in Microsoft Windows 98, 98 Second Edition, Millennium Edition, NT 4.0, NT 4.0 Terminal Server Edition, Windows 2000, and Windows XP allows remote attackers to execute code via (1) a long parameter to the Alink function, or (2) script containing a long argument to the showHelp function.
Affected Products
46 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Windows 2000Microsoft | See advisory | n/a |
| Windows 2000 Terminal ServicesMicrosoft | See advisory | n/a |
| Windows 98Microsoft | See advisory | n/a |
| Windows 98seMicrosoft | See advisory | n/a |
| Windows MeMicrosoft | See advisory | n/a |
Timeline
Publicly disclosed
Oct 10, 2002
Last updated
Apr 15, 2026
References
- advisorywin-html-help-bo(10253)
- exploitExploitDB-21902
- other20021003 Buffer Overflow in IE/Outlook HTML Help
- other20021009 Thor Larholm security advisory TL#004
- other20021010 prover of concept code of windows help overflow
FAQ
Common Questions.
Buffer overflow in the HTML Help ActiveX Control (hhctrl.ocx) in Microsoft Windows 98, 98 Second Edition, Millennium Edition, NT 4.0, NT 4.0 Terminal Server Edition, Windows 2000, and Windows XP allows remote attackers to execute code via (1) a long parameter to the Alink function, or (2) script containing a long argu…
Affected: Windows 2000 (Microsoft); Windows 2000 Terminal Services (Microsoft); Windows 98 (Microsoft), among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because public exploit code exists for a high-severity flaw.
Is CVE-2002-0693 On Your Attack Surface?
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